WO2017118206A1 - Pixel structure, driving method therefor, organic electroluminescent display panel, and display device - Google Patents

Abstract

A pixel structure, a driving method therefor, an organic electroluminescent display panel, and a display device. The pixel structure comprises N light emitting elements (1_n), pixel compensation circuits (2_n) connected to the light emitting elements (1_n) in a one-to-one correspondence, a potential switching circuit (3), and a voltage input control circuit (4). The multiple pixel compensation circuits (2_n) are all connected to the same potential switching circuit (3) and the same voltage input control circuit (4), so that the multiple pixel compensation circuits (2_n) share the potential switching circuit (3) and the voltage input control circuit (4), thereby reducing the areas occupied by the pixel compensation circuits (2_n) in pixel regions, and increasing the aperture ratio of each pixel region.

Description

Pixel structure and driving method, organic electroluminescence display panel and display device Technical field

Embodiments of the present invention relate to a pixel structure, a driving method thereof, an organic electroluminescence display panel, and a display device.

Background technique

Organic Light Emitting Diode (OLED) displays are one of the hotspots in the field of flat panel display research. Compared with Liquid Crystal Display (LCD), OLED display has the advantages of low energy consumption, low production cost, self-illumination, wide viewing angle and fast response. Therefore, at present, in the display field of mobile phones and digital cameras, OLED displays Has begun to replace the traditional LCD. In the OLED display, the pixel compensation circuit design for controlling the illumination of the light-emitting device is the core technical content of the OLED display, and has important research significance.

For example, the OLED display includes a plurality of pixel regions, each of the pixel regions including a light emitting device and a pixel compensation circuit for driving the light emitting device to be correspondingly connected to the light emitting device. The pixel compensation circuit includes, for example, a compensation module and a control module for supplying a power supply voltage and a reference signal to the compensation module, each of which includes, for example, a plurality of switching transistors. Therefore, in an OLED display, such a pixel compensation circuit occupies a large area in a pixel region, thereby lowering the pixel aperture ratio of the OLED display.

Summary of the invention

Embodiments of the present invention provide a pixel structure, a driving method thereof, an organic electroluminescence display panel, and a display device, which can simplify each pixel by sharing a plurality of pixel compensation circuits with the same voltage input control circuit and the same potential conversion circuit. The structure of the compensation circuit is to increase the aperture ratio of the pixel region.

Embodiments of the present invention provide a pixel structure including N light emitting devices, a first power terminal, a second power terminal, a reference signal terminal, a first potential conversion terminal, a second potential conversion terminal, a charging control terminal, and an illumination control And a potential input circuit, a voltage input control circuit, and a pixel compensation circuit connected in one-to-one correspondence with the first ends of the respective light-emitting devices; wherein N is a positive integer greater than zero.

The potential conversion circuit includes a first input terminal, a second input terminal, a third input terminal, a first control terminal, a second control terminal, a first output terminal, and a second output terminal, and the first input of the potential conversion circuit The terminal is connected to the first power terminal, the second input terminal is connected to the second power terminal, the third input terminal is connected to the reference signal terminal, the first control terminal is connected to the first potential conversion terminal, and the second control terminal is coupled to the second potential terminal. Connected to the end, the first output end is connected to each of the pixel compensation circuits, and the second output end is connected to the second end of each of the light emitting devices; the potential conversion circuit is configured to be under the control of the first potential conversion end Supplying a voltage of the first power supply terminal to each of the light emitting devices, and simultaneously supplying a voltage of the reference signal terminal to each of the pixel compensation circuits, and controlling the second power supply end under the control of the second potential conversion end Voltages are supplied to each of the light emitting devices and each of the pixel compensation circuits.

The voltage input control circuit includes an input end, a first output end, a second output end, a first control end, and a second control end, and an input end of the voltage input control circuit is connected to the first power supply end, first The output end and the second output end are respectively connected to each of the pixel compensation circuits, the first control end is connected to the charging control end, and the second control end is connected to the illumination control end; the voltage input control circuit is configured to be in the charging The voltage of the first power supply terminal is supplied to each of the pixel compensation circuits under control of the control terminal to charge each of the pixel compensation circuits, and the voltage of the first power supply terminal is supplied to each under the control of the light emission control terminal The pixel compensation circuit controls the pixel compensation circuit to drive the light emitting device to emit light.

The voltage of the first power terminal and the voltage of the reference signal terminal are both higher than the voltage of the second power terminal.

The embodiment of the invention further provides a driving method for the above pixel structure, which comprises: a charging phase, a discharging phase, a holding phase and a lighting phase.

In the charging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each of the light emitting devices under the control of the first potential converting end, and simultaneously supplies the voltage of the reference signal terminal Providing a second node in each of the pixel compensation circuits; the voltage input control circuit provides a voltage of the first power supply terminal to a first node in each of the pixel compensation circuits under the control of the charge control terminal; The compensation control module implements charging under the common control of the first node and the second node.

In the discharging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each of the light emitting devices under the control of the first potential converting end, and simultaneously supplies the voltage of the reference signal terminal Giving a second node in each of said pixel compensation circuits; said data writing module is The signal of the data signal end is supplied to the first end of the drive control module under the control of the scan signal end; the compensation control module causes the first node and the drive control under the control of the compensation control end The first end of the module is turned on, and the threshold voltage of the drive control module and the voltage of the first end of the drive control module are stored in the first node.

In the holding phase, the potential conversion circuit supplies the voltage of the second power supply terminal to the second end of the light emitting device and the first of the pixel compensation circuits respectively under the control of the second potential conversion end Two nodes.

In the light emitting phase, the potential conversion circuit supplies the voltage of the second power supply terminal to the second end of each of the light emitting devices and each of the pixel compensation circuits under the control of the second potential conversion end a second node; the voltage input control circuit supplies the voltage of the first power terminal to the third end of the drive control module in each of the pixel compensation circuits under the control of the illumination control terminal; the drive control module is The light emitting device emits light under the control of the first node and the third end of the drive control module.

The embodiment of the present invention further provides an organic electroluminescent display panel, which includes an M column region arranged in a matrix, and the pixel structure provided by the embodiment of the present invention corresponding to each row region. The number of the light emitting devices in each of the pixel structures is equal; M is equal to N; the light emitting device and the pixel compensation circuit in each of the pixel structures are disposed in a region of a corresponding row, and a light emitting device is disposed in one region and A pixel compensation circuit connected to the light emitting device.

The embodiment of the invention further provides a display device comprising the above-mentioned organic electroluminescent display panel provided by the embodiment of the invention.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It is obvious that the drawings in the following description relate only to some embodiments of the present invention, and are not intended to limit the present invention. .

1a is a schematic structural diagram of a pixel structure according to an embodiment of the present invention;

FIG. 1b is a second schematic structural diagram of a pixel structure according to an embodiment of the present disclosure;

2a is a schematic diagram of a specific structure of a pixel structure according to an embodiment of the present invention;

2b is a second schematic structural diagram of a pixel structure according to an embodiment of the present disclosure;

3a is a third schematic structural diagram of a pixel structure according to an embodiment of the present invention;

FIG. 3b is a fourth schematic diagram of a specific structure of a pixel structure according to an embodiment of the present disclosure;

4a is a circuit timing diagram of the pixel structure provided in FIG. 2b;

Figure 4b is a circuit timing diagram of the pixel structure provided in Figure 3b;

FIG. 5 is a schematic structural diagram of a pixel structure in an organic electroluminescence display panel according to an embodiment of the present invention.

detailed description

The technical solutions of the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. It is apparent that the described embodiments are part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention.

Unless otherwise defined, technical terms or scientific terms used in the present disclosure are intended to be in the ordinary meaning of those of ordinary skill in the art. The words "first," "second," and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different components. The word "comprising" or "comprises" or the like means that the element or item preceding the word is intended to be in the The words "connected" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate the relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may also change accordingly.

The specific embodiments of the pixel structure, the driving method, the organic electroluminescent display panel and the display device provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

A pixel structure is provided in the embodiment of the present invention. As shown in FIG. 1a, the pixel structure includes N light emitting devices 1_n (n=1, 2, 3...N) and a first end 1a of each of the light emitting devices 1_n. a corresponding pixel compensation circuit 2_n; the pixel structure further includes a first power terminal VDD, a second power terminal VSS, a reference signal terminal Ref, a first potential conversion terminal E1, a second potential conversion terminal E2, a charging control terminal DC, The light-emitting control terminal EM, a potential conversion circuit 3 and a voltage input control circuit 4. In the pixel structure, N is a positive integer greater than 0, for example, N is an integer greater than or equal to 2, such that the plurality of pixel compensation circuits 2_n share a potential conversion circuit 3 and a voltage input Control circuit 4.

The first input terminal 3a of the potential conversion circuit 3 is connected to the first power supply terminal VDD, the second input terminal 3b is connected to the second power supply terminal VSS, and the third input terminal 3c is connected to the reference signal terminal Ref. The first control terminal 3d and the A potential conversion terminal E1 is connected, a second control terminal 3e is connected to the second potential conversion terminal E2, a first output terminal 3f is connected to each pixel compensation circuit 2_n, and a second output terminal 3g is connected to the second terminal 1b of each of the light emitting devices 1_n. The potential conversion circuit 3 is configured to supply the voltage of the first power supply terminal VDD to the respective light emitting devices 1_n under the control of the first potential conversion terminal E1, and supply the voltage of the reference signal terminal Ref to each of the pixel compensation circuits 2_n. The voltage of the second power supply terminal VSS is supplied to each of the light-emitting devices 1_n and the respective pixel compensation circuits 2_n under the control of the two-potential conversion terminal E2.

The input terminal 4a of the voltage input control circuit 4 is connected to the first power supply terminal VDD, and the first output terminal 4b and the second output terminal 4c are respectively connected to the respective pixel compensation circuits 2_n (as shown in FIG. 1a, each pixel compensation circuit 2_n is Connecting the first output terminal 4b and the second output terminal 4c), the first control terminal 4d is connected to the charging control terminal DC, the second control terminal 4e is connected to the lighting control terminal EM, and the voltage input control circuit 4 is used at the charging control terminal DC. The voltage of the first power supply terminal VDD is supplied to each pixel compensation circuit 2_n to charge each pixel compensation circuit 2_n, and the voltage of the first power supply terminal VDD is supplied to each pixel compensation circuit under the control of the light emission control terminal EM. 2_n, the light-emitting device 1_n is driven to emit light by the control pixel compensation circuit 2_n.

The voltage of the first power terminal VDD and the voltage of the reference signal terminal Ref are both higher than the voltage of the second power terminal VSS.

The pixel structure provided by the embodiment of the present invention includes N (N is a positive integer greater than 0) light-emitting devices, a pixel compensation circuit connected in one-to-one correspondence with each light-emitting device, and a potential conversion circuit and a voltage input control circuit; The pixel structure provided by the embodiment of the invention can realize that a plurality of pixel compensation circuits are connected to the same potential conversion circuit and the same voltage input control circuit, which is equivalent to making a plurality of pixel compensation circuits share one potential conversion circuit and one voltage input control circuit. Compared with the manner in which each pixel compensation circuit includes a control module for controlling the input voltage of the power supply voltage and the reference signal, the structure of each pixel compensation circuit can be simplified, thereby reducing the occupied area of the pixel compensation circuit in the pixel region, and further Increase the aperture ratio of each pixel area.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 1b (taking N equal to 1 as an example), the pixel compensation circuit 2_1 includes a data writing module 21, a compensation control module 22, and a driving control module 23.

The data writing module 21 has a first end 21a connected to the scanning signal end Sc, a second end 21b connected to the data signal end Da, and a third end 21c respectively connected to the first end 23a of the driving control module 23 and the light emitting device 1_1. One end 1a is connected; the data writing module 21 is for supplying the signal of the data signal terminal Da to the first end 23a of the drive control module 23 under the control of the scanning signal terminal Sc.

The compensation control module 22 has a first end 22a connected to the compensation control end EC, and a second end 22b respectively connected to the first output end 4b of the voltage input control circuit 4, the second end 23b of the drive control module 23, and the connection voltage input control circuit The first output terminal 4b of 4 is connected to the first node A of the second terminal 23b of the drive control module 23, and the third terminal 22c is respectively connected to the second output terminal 4c of the voltage input control circuit 4 and the third terminal of the drive control module 23. 23c is connected, the fourth end 22d is connected to the first output end 3f of the potential conversion circuit 3 and the second node B connecting the compensation control module 22 and the potential conversion circuit 3; the compensation control module 22 is used for: in the potential conversion circuit 3 The charging is realized under the control of an output terminal 3f and the first output terminal 4b of the voltage input control circuit 4, and the first node A and the first terminal 23a of the driving control module 23 are turned on under the control of the compensation control terminal EC to The threshold voltage of the drive control module 23 and the voltage of the first end 23a of the drive control module 23 are all stored in the first node A.

The driving control module 23 is configured to drive the light-emitting device 1_1 corresponding to the pixel compensation circuit 2_1 to emit light under the control of the first node A and the second output terminal 4c of the voltage input control circuit 4.

The pixel compensation circuit can cooperate with the three modules of the data writing module, the compensation control module and the driving control module to enable the driving control module in each pixel compensation circuit to drive the operating current of the light emitting device to emit only the voltage and reference signal of the data signal end. The voltage at the terminal is independent of the threshold voltage in the drive control module and the voltage at the first power supply terminal, which can avoid the influence of the threshold voltage and the voltage drop (IR Drop) on the current flowing through the light emitting device, thereby maintaining the operating current for driving the light emitting device to emit light. Stable, it can improve the uniformity of the brightness of the display area in the display device.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 1b, the potential conversion circuit 3 may include a first conversion module 31 and a second conversion module 32.

The first conversion module 31 is respectively connected to the first power terminal VDD, the reference signal terminal Ref, the first potential conversion terminal E1, the first output terminal 3f of the potential conversion circuit 3, and the second output terminal 3g of the potential conversion circuit 3; A conversion module 31 is configured to supply the voltage of the reference signal terminal Ref to each of the pixel compensation circuits 2_1 under the control of the first potential conversion terminal E1, while supplying the voltage of the first power supply terminal VDD to the respective light emitting devices 1_1.

The second conversion module 32 is respectively connected to the second power terminal VSS, the second potential conversion terminal E2, the first output terminal 3f of the potential conversion circuit 3, and the second output terminal 3g of the potential conversion circuit 3; The voltage of the second power supply terminal VSS is supplied to each of the light-emitting devices 1_1 and the respective pixel compensation circuits 2_1 under the control of the second potential conversion terminal E2.

The above pixel structure provided by the embodiment of the present invention will be described in detail below with reference to specific embodiments. It should be noted that the embodiments of the present invention are only for better explanation of the present invention, but do not limit the present invention.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b (taking N equal to 1 as an example), the driving control module 23 may include a driving transistor M0; the gate M01 of the driving transistor M0 and the first A node A is connected, a source M02 is connected to the second output terminal 4c of the voltage input control circuit 4, and a drain M03 is connected to the first terminal 1a of the light-emitting device 1_1.

For example, the light emitting device in the above pixel structure provided by the embodiment of the present invention is an organic electroluminescent diode. The light emitting device realizes light emission under the action of the saturation current of the driving transistor.

For example, in the above pixel structure provided by the embodiment of the present invention, the driving transistor that drives the light emitting device to emit light is an N-type transistor. In order to ensure that the driving transistor can work normally, the voltage of the corresponding first power terminal is a positive voltage, and the voltage of the second power terminal is lower than the voltage of the first power terminal.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b, the first conversion module 31 may include: a first switching transistor M1 and a second switching transistor M2; a gate of the first switching transistor M1 The pole M11 is connected to the first potential conversion terminal E1, the source M12 is connected to the first power terminal VDD, the drain M13 is connected to the second output terminal 3g of the potential conversion circuit 3, and the gate M21 of the second switching transistor M2 is first. The potential conversion terminal E1 is connected, the source M22 is connected to the reference signal terminal Ref, and the drain M23 is connected to the first output terminal 3f of the potential conversion circuit 3.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the first switching transistor M1 and the second switching transistor M2 may be N-type switching transistors; or, as shown in FIG. 3a and FIG. 3b. It is to be noted that the first switching transistor M1 and the second switching transistor M2 may also be P-type switching transistors, which are not limited herein.

The above is only a specific structure of the first conversion module in the pixel structure. For example, the specific structure of the first conversion module is not limited to the above structure provided by the embodiment of the present invention, and may be other structures known to those skilled in the art. Not limited.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b, The second conversion module 32 may include: a third switching transistor M3 and a fourth switching transistor M4; a gate M31 of the third switching transistor M3 is connected to the second potential conversion terminal E2, and a source M32 is connected to the second power terminal VSS, and the drain The pole M33 is connected to the second output terminal 3g of the potential conversion circuit 3; the gate M41 of the fourth switching transistor M4 is connected to the second potential conversion terminal E2, the source M42 is connected to the second power supply terminal VSS, and the drain M43 is connected to the potential The first output 3f of the circuit 3 is connected.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the third switching transistor M3 and the fourth switching transistor M4 may be P-type switching transistors; or, as shown in FIG. 3a and FIG. 3b. The third switching transistor M3 and the fourth switching transistor M4 may also be N-type switching transistors, which are not limited herein.

The above is only a specific structure of the second conversion module in the pixel structure. For example, the specific structure of the second conversion module is not limited to the above structure provided by the embodiment of the present invention, and may be other structures known to those skilled in the art. Not limited.

Further, for example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2b, the first switching transistor M1 and the second switching transistor M2 are N-type switching transistors, and the third switching transistor M3 and the fourth switch The transistor M4 is a P-type switching transistor; or, as shown in FIG. 3b, the first switching transistor M1 and the second switching transistor M2 are P-type switching transistors, and the third switching transistor M3 and the fourth switching transistor M4 are N-type switching transistors. . In this way, the first potential conversion terminal E1 and the second potential conversion terminal E2 can be set to the same signal terminal, which can reduce the number of signal lines, thereby further increasing the aperture ratio of the pixel region.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b, the voltage input control circuit 4 includes: a fifth switching transistor M5 and a sixth switching transistor M6; and a gate of the fifth switching transistor M5. M51 is connected to the charging control terminal DC, the source M52 is connected to the first power terminal VDD, the drain M53 is connected to the first output terminal 4b of the voltage input control circuit 4, and the gate M61 of the sixth switching transistor M6 is connected to the illumination control terminal EM. Connected, the source M62 is connected to the first power terminal VDD, and the drain M63 is connected to the second output terminal 4c of the voltage input control circuit 4.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the fifth switching transistor M5 may be an N-type switching transistor; or, as shown in FIG. 3a and FIG. 3b, the fifth switching transistor M5 can also be a P-type switching transistor, which is not limited herein.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the sixth switching transistor M6 may be an N-type switching transistor; or, as shown in FIG. 3a and FIG. 3b, The sixth switching transistor M6 may also be a P-type switching transistor, which is not limited herein.

The above is only a specific structure of the voltage input control circuit in the pixel structure. For example, the specific structure of the voltage input control circuit is not limited to the above structure provided by the embodiment of the present invention, and may be other structures known to those skilled in the art. Not limited.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b, the data writing module 21 may include a seventh switching transistor M7; the gate M71 of the seventh switching transistor M7 and the scanning signal end Sc Connected, the source M72 is connected to the data signal terminal Da, and the drain M73 is connected to the first end 1a of the light emitting device 1_1.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the seventh switching transistor M7 may be an N-type switching transistor; or, as shown in FIG. 3a and FIG. 3b, the seventh switching transistor M7 can also be a P-type switching transistor, which is not limited herein.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a to FIG. 3b, the compensation control module 22 includes: an eighth switching transistor M8 and a capacitor C; a gate M81 of the eighth switching transistor M8 and a compensation control The terminal EC is connected, the source M82 is connected to the second output terminal 4c of the voltage input control circuit 4, the drain M83 is connected to the first node A, and the capacitor C is connected between the first node A and the second node B.

For example, in the above pixel structure provided by the embodiment of the present invention, as shown in FIG. 2a and FIG. 2b, the eighth switching transistor M8 may be an N-type switching transistor; or, as shown in FIG. 3a and FIG. 3b, the eighth switching transistor M8 can also be a P-type switching transistor, which is not limited herein.

Further, for example, the P-type switching transistor is turned off under a high potential and turned on under a low potential; the N-type switching transistor is turned on under a high potential and is turned off under a low potential.

It should be noted that, in the above pixel structure provided by the embodiment of the present invention, the driving transistor and the switching transistor may be a thin film transistor (TFT) or a metal oxide semiconductor field effect transistor (MOS, Metal Oxide Scmiconductor). ), here is not limited. In a specific implementation, the sources and drains of these transistors can be interchanged without specific distinction. In the description of the specific embodiment, the case where the driving transistor and the switching transistor are both thin film transistors will be described as an example.

The working process of the above pixel structure provided by the embodiment of the present invention is described below by taking the pixel structure shown in FIG. 2b and FIG. 3b as an example. In the following description, 1 indicates a high potential, and 0 indicates a low potential. It should be noted that 1 and 0 are logic potentials, which are only for better explanation of the specific working process of the embodiment of the present invention, and are not specifically implemented. Applied to the gate of each switching transistor The potential on the pole.

Embodiment 1

Taking the pixel structure shown in FIG. 2b as an example, the third switching transistor M3 and the fourth switching transistor M4 are both P-type switching transistors, and the remaining switching transistors are all N-type switching transistors; the voltage of the second power supply terminal VSS is As an example, the corresponding input/output timing diagram is as shown in FIG. 4a, and includes four stages: a charging phase T1, a discharging phase T2, a holding phase T3, and a lighting phase T4.

In the charging phase T1, E1=1, EM=0, DC=1, EC=0, Da=0, Sc=1.

The first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, and the seventh switching transistor M7 are all turned on; the third switching transistor M3, the fourth switching transistor M4, the sixth switching transistor M6, and the eighth switching transistor M8 Both are closed. The turned-on second switching transistor M2 writes the voltage V _{ref of the} reference signal terminal Ref to the second node B, so that the voltage of the second node B is V _B =V _ref ; the fifth switching transistor M5 that is turned on will be the first power terminal The voltage V _{dd of} VDD is written into the first node A, so the voltage of the first node A is V _A = V _ref , the capacitor C starts to be charged, the driving transistor is turned on under the control of the first node; the turned-on seventh switching transistor M7 Writing a low potential voltage of the data signal terminal Da to the first end of the light emitting device 1_1, and turning on the first switching transistor M1 to write the voltage V _{dd of the} first power terminal VDD to the second end of the light emitting device 1_1. Therefore, the light emitting device 1_1 does not emit light.

In the discharge phase T2, E1=1, EM=0, DC=0, EC=1, Da=1, Sc=1.

The first switching transistor M1, the second switching transistor M2, the seventh switching transistor M7, and the eighth switching transistor M8 are both turned on; the third switching transistor M3, the fourth switching transistor M4, the fifth switching transistor M5, and the sixth switching transistor M6 Both are closed. The turned-on second switching transistor M2 writes the voltage V _{ref of the} reference signal terminal Ref to the second node B, the voltage of the second node B V _B =V _ref , and the turned-on seventh switching transistor M7 turns the data signal terminal Da The high-potential voltage V _{data is} written to the drain of the driving transistor M0; the turned-on eighth switching transistor M8 turns the driving transistor M0 into a diode, the diode is turned on, and the capacitor C starts to discharge until the voltage of the first node A becomes V. _{When data} +V _th , the diode is turned off, and the capacitor stops discharging. At this time, the voltage difference across the capacitor C is V _data +V _th -V _ref1 , thereby realizing the threshold voltage V _th of the driving transistor M0 at the gate of the driving transistor M0. storage.

In the hold phase T3, E1=0, EM=0, DC=0, EC=0, Da=0, Sc=0.

The third switching transistor M3 and the fourth switching transistor M4 are both turned on; the first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, the sixth switching transistor M6, the seventh switching transistor M7, and the eighth switching transistor M8 Both are closed. The turned-on third switching transistor M3 writes the voltage 0 of the second power supply terminal V2 to the second end of the light emitting device 1_1, and the source of the driving transistor M0 has no voltage writing, so the light emitting device 1_1 does not emit light; The switching transistor M3 writes the voltage 0 of the second power terminal V2 to the second node B, that is, the second terminal c2 of the capacitor C, so that the voltage of the second terminal c2 of the capacitor C changes from V _ref to 0, according to the principle of conservation of capacitance In order to ensure that the voltage difference between the two ends of the first capacitor C1 is still V _data +V _th -V _ref , the voltage of the first end c1 of the capacitor C jumps from V _data +V _th to V _data +V _th -V _ref .

In the illuminating phase T4, E1=0, EM=1, DC=0, EC=0, Da=0, Sc=0.

The third switching transistor M3, the fourth switching transistor M4, and the sixth switching transistor M6 are both turned on; the first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, the seventh switching transistor M7, and the eighth switching transistor M8 Both are closed. The turned-on third switching transistor M3 writes the voltage 0 of the second power supply terminal V2 to the second end of the light emitting device 1_1 and the second node B, that is, the second end c2 of the capacitor C, so that the second end c2 of the capacitor C The voltage is still 0; the turned-on sixth switching transistor M6 writes the voltage V _{dd of the} first power terminal VDD to the source of the driving transistor M0; since the driving transistor M0 operates in a saturated state, according to the saturation state current characteristic, it flows The operating current I for driving the transistor M0 and for driving the light-emitting device 1_1 to emit light satisfies the formula: I=K(V _gs -V _th ) ² =K(V _data +V _th -V _ref -V _th ) ² =K(V _data -V _ref ) ² , where K is a structural parameter, which is relatively stable in the same structure and can be counted as a constant. The gate-source voltage V _gs = V _data + V _th - V _{ref of the} driving transistor M0. By the above equation, the driving current of the driving transistor M0 is only related to the voltage V _data voltage V _ref and the data signal terminal Da of the reference signal terminal Ref, and with the threshold voltage V _th and the first supply terminal of the driving transistor M0 voltage V _dd Irrelevantly, the drift of the threshold voltage _Vth due to the process of the driving transistor M0 and the long-time operation, and the influence of the IR Drop on the current flowing through the light-emitting device are solved, thereby keeping the operating current of the light-emitting device 1_1 stable, thereby ensuring The normal operation of the light emitting device 1_1.

Embodiment 2

Taking the pixel structure shown in FIG. 3b as an example, wherein the third switching transistor M3 and the fourth switching transistor M4 are N-type switching transistors, and the remaining switching transistors are P-type switching transistors; each P-type switching transistor acts at a low potential The lower conduction is turned off under the action of high potential; each N-type switching transistor is turned on under the action of high potential, and is cut off under the action of low potential; taking the voltage of the second power supply terminal as 0V as an example, the corresponding input and output timing diagram is as shown in the figure 4b, including: charging phase T1, discharging phase T2, the holding phase T3 and the lighting phase T4 are in four stages.

In the charging phase T1, E1=0, EM=1, DC=0, EC=1, Da=1, Sc=0.

The first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, and the seventh switching transistor M7 are all turned on; the third switching transistor M3, the fourth switching transistor M4, the sixth switching transistor M6, and the eighth switching transistor M8 Both are closed. The turned-on second switching transistor M2 writes the voltage V _{ref of the} reference signal terminal Ref to the second node B, so that the voltage of the second node B is V _B =V _ref ; the fifth switching transistor M5 that is turned on will be the first power terminal The voltage V _{dd of} VDD is written into the first node A, so the voltage of the first node A is V _A = V _ref , the capacitor C starts to be charged, the driving transistor is turned on under the control of the first node; the turned-on seventh switching transistor M7 Writing a low potential voltage of the data signal terminal Da to the first end of the light emitting device 1_1, and turning on the first switching transistor M1 to write the voltage V _{dd of the} first power terminal VDD to the second end of the light emitting device 1_1. Therefore, the light emitting device 1_1 does not emit light.

In the discharge phase T2, E1=0, EM=1, DC=1, EC=0, Da=0, Sc=0.

The first switching transistor M1, the second switching transistor M2, the seventh switching transistor M7, and the eighth switching transistor M8 are both turned on; the third switching transistor M3, the fourth switching transistor M4, the fifth switching transistor M5, and the sixth switching transistor M6 Both are closed. The turned-on second switching transistor M2 writes the voltage V _{ref of the} reference signal terminal Ref to the second node B, the voltage of the second node B V _B =V _ref , and the turned-on seventh switching transistor M7 turns the data signal terminal Da The high-potential voltage V _{data is} written to the drain of the driving transistor M0; the turned-on eighth switching transistor M8 turns the driving transistor M0 into a diode, the diode is turned on, and the capacitor C starts to discharge until the voltage of the first node A becomes V. _{When data} +V _th , the diode is turned off, and the capacitor stops discharging. At this time, the voltage difference across the capacitor C is V _data +V _th -V _ref1 , thereby realizing the threshold voltage V _th of the driving transistor M0 at the gate of the driving transistor M0. storage.

In the hold phase T3, E1=1, EM=1, DC=1, EC=1, Da=1, and Sc=1.

The third switching transistor M3 and the fourth switching transistor M4 are both turned on; the first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, the sixth switching transistor M6, the seventh switching transistor M7, and the eighth switching transistor M8 Both are closed. The turned-on third switching transistor M3 writes the voltage 0 of the second power supply terminal V2 to the second end of the light emitting device 1_1, and the source of the driving transistor M0 has no voltage writing, so the light emitting device 1_1 does not emit light; The switching transistor M3 writes the voltage 0 of the second power terminal V2 to the second node B, that is, the second terminal c2 of the capacitor C, so that the voltage of the second terminal c2 of the capacitor C changes from V _ref to 0, according to the principle of conservation of capacitance In order to ensure that the voltage difference between the two ends of the first capacitor C1 is still V _data +V _th -V _ref , the voltage of the first end c1 of the capacitor C jumps from V _data +V _th to V _data +V _th -V _ref .

In the illumination phase T4, E1=1, EM=0, DC=1, EC=1, Da=1, and Sc=1.

The third switching transistor M3, the fourth switching transistor M4, and the sixth switching transistor M6 are both turned on; the first switching transistor M1, the second switching transistor M2, the fifth switching transistor M5, the seventh switching transistor M7, and the eighth switching transistor M8 Both are closed. The turned-on third switching transistor M3 writes the voltage 0 of the second power supply terminal V2 to the second end of the light emitting device 1_1 and the second node B, that is, the second end c2 of the capacitor C, so that the second end c2 of the capacitor C The voltage is still 0; the turned-on sixth switching transistor M6 writes the voltage V _{dd of the} first power terminal VDD to the source of the driving transistor M0; since the driving transistor M0 operates in a saturated state, according to the saturation state current characteristic, it flows The operating current I for driving the transistor M0 and for driving the light-emitting device 1_1 to emit light satisfies the formula: I=K(V _gs -V _th ) ² =K(V _data +V _th -V _ref -V _th ) ² =K(V _data -V _ref ) ² , where K is a structural parameter, which is relatively stable in the same structure and can be counted as a constant. The gate-source voltage V _gs = V _data + V _th - V _{ref of the} driving transistor M0. By the above equation, the driving current of the driving transistor M0 is only related to the voltage V _data voltage V _ref and the data signal terminal Da of the reference signal terminal Ref, and with the threshold voltage V _th and the first supply terminal of the driving transistor M0 voltage V _dd Irrelevantly, the threshold voltage _Vth drift due to the process of the driving transistor M0 and the long-time operation, and the influence of the voltage drop (IR Drop) on the current flowing through the light emitting device are solved, thereby stabilizing the operating current of the light emitting device 1_1. In turn, the normal operation of the light emitting device 1_1 is ensured.

Based on the same inventive concept, an embodiment of the present invention further provides a driving method for any of the above pixel structures, including: a charging phase, a discharging phase, a holding phase, and a lighting phase.

In the charging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each light emitting device under the control of the first potential converting end, and supplies the voltage of the reference signal terminal to the second node in each pixel compensation circuit; The input control circuit supplies the voltage of the first power terminal to the first node in each pixel compensation circuit under the control of the charging control terminal; the data writing module provides the signal of the data signal terminal to the first of the driving control module under the control of the scanning signal terminal And the first end of the light emitting device; the driving control module turns on the first end and the third end of the driving control module under the control of the compensation control end; the compensation control module realizes charging under the common control of the first node and the second node.

In the discharging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each of the light emitting devices under the control of the first potential converting end, and supplies the voltage of the reference signal terminal to each pixel. a second node in the circuit; the data writing module provides the signal of the data signal end to the first end of the driving control module and the first end of the light emitting device under the control of the scanning signal end; the compensation control module is controlled under the control of the compensation control end The first node is electrically connected to the first end of the driving control module, and stores the threshold voltage of the driving control module and the voltage of the first end of the driving control module at the first node.

In the holding phase, the potential conversion circuit supplies the voltage of the second power supply terminal to the second end of the light emitting device and the second node of each pixel compensation circuit under the control of the second potential conversion end.

In the illuminating phase, the potential conversion circuit supplies the voltage of the second power terminal to the second end of each illuminating device and the second node of each pixel compensating circuit under the control of the second potential converting end; the voltage input control circuit is at the illuminating control end The voltage of the first power terminal is controlled to be supplied to the third end of the driving control module in each pixel compensation circuit; the driving control module drives the light emitting device to emit light under the control of the first node and the third end of the driving control module.

Based on the same inventive concept, an embodiment of the present invention further provides an organic electroluminescence display panel, as shown in FIG. 5, including an M column region 01 arranged in a matrix (see 01_1-01_M), and further including each row region 01. The one-to-one corresponding pixel structure provided by the embodiment of the present invention, and the number of the light-emitting devices in each pixel structure is equal; wherein M is equal to N; the light-emitting device and the pixel compensation circuit in each pixel structure are disposed in corresponding rows In the area 01, and one area 01 is provided with one light emitting device and one pixel compensation circuit connected to the light emitting device.

For example, the organic electroluminescence display panel further includes a plurality of gate lines GT extending in the row direction of the pixels and sequentially arranged, and a plurality of data lines DT (see DT_1-DT_N) extending in the column direction of the pixels and sequentially arranged, each row The gate line corresponds to the scan signal end of each pixel compensation circuit in the pixel structure of the connected row, to input a scan signal to each pixel compensation circuit; each column of data lines corresponds to each pixel compensation circuit in each row of pixel structures connected to the column The data signal terminal inputs a data signal to each pixel compensation circuit.

For example, in the organic electroluminescence display panel, the high potential of the voltage of the control signal for controlling the switching transistor in each pixel compensation circuit is 20V to 30V, and the low potential is -8V.

For example, in the above organic electroluminescent display panel provided by the embodiment of the present invention, the potential conversion circuit and the voltage input control circuit in each pixel structure may be fabricated on the array substrate, or may be fabricated in the peripheral circuit chip, and are not used herein. limited. When the potential conversion circuit and the voltage input control circuit are fabricated in the peripheral circuit chip, the high potential of the voltage of the control signal for controlling each of the switching transistors is, for example, 3.3 V, and the low potential is, for example, 0 V.

Since the principle of solving the problem of the organic electroluminescent display panel is similar to the foregoing pixel structure, the implementation of the organic electroluminescent display panel can be referred to the implementation of the pixel structure, and the repeated description is omitted.

Based on the same inventive concept, an embodiment of the present invention further provides a display device including the above-described organic electroluminescent display panel provided by the embodiment of the present invention. The display device may be a display, a mobile phone, a television, a notebook, an all-in-one, etc., and other essential components of the display device are understood by those of ordinary skill in the art, and will not be described herein. As a limitation of the invention.

The embodiment of the invention provides a pixel structure, a driving method thereof, an organic electroluminescence display panel and a display device. The pixel structure comprises N light emitting devices, a pixel compensation circuit connected in one-to-one correspondence with each light emitting device, and a potential a conversion circuit and a voltage input control circuit; by connecting a plurality of pixel compensation circuits to the same potential conversion circuit and the same voltage input control circuit (in this case, N is a positive integer greater than or equal to 2), which is equivalent to Having a plurality of pixel compensation circuits share a potential conversion circuit and a voltage input control circuit, which simplifies each pixel as compared with a method in which each pixel compensation circuit includes a control module for controlling a power supply voltage and an input of a reference signal. The structure of the compensation circuit can thereby reduce the occupied area of the pixel compensation circuit in the pixel region (see the region 01 in FIG. 5), thereby increasing the aperture ratio of each pixel region.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

The present application claims the priority of the Chinese Patent Application No. 201610006810.7 filed on Jan. 4, 2016, the content of which is hereby incorporated by reference.

Claims (14)

A pixel structure comprising N light emitting devices, a first power terminal, a second power terminal, a reference signal terminal, a first potential conversion terminal, a second potential conversion terminal, a charging control terminal, an illumination control terminal, a potential conversion circuit, a voltage input control circuit, and a pixel compensation circuit connected in one-to-one correspondence with the first ends of the respective light-emitting devices; wherein N is a positive integer greater than 0; The potential conversion circuit includes a first input end, a second input end, a third input end, a first control end, a second control end, a first output end, and a second output end, the first input end and the The first power terminal is connected to the second power terminal, the third input terminal is connected to the reference signal terminal, and the first control terminal is connected to the first potential conversion terminal The second control end is connected to the second potential conversion end, the first output end is connected to each of the pixel compensation circuits, and the second output end is connected to the second end of each of the light emitting devices; The potential conversion circuit is configured to supply a voltage of the first power supply terminal to each of the light emitting devices under control of the first potential conversion terminal, and supply a voltage of the reference signal terminal to each of the pixel compensation circuits Providing a voltage of the second power supply terminal to each of the light emitting device and each of the pixel compensation circuits under the control of the second potential conversion end; The voltage input control circuit includes an input end, a first output end, a second output end, a first control end, and a second control end, wherein the input end is connected to the first power supply end, and the voltage input control circuit is The first output end and the second output end are respectively connected to the pixel compensation circuits, and the first control end of the voltage input control circuit is connected to the charging control end, and the second control end of the voltage input control circuit is The light emission control terminal is connected; the voltage input control circuit is configured to provide a voltage of the first power supply terminal to each of the pixel compensation circuits under the control of the charge control terminal to charge each of the pixel compensation circuits Providing a voltage of the first power supply terminal to each of the pixel compensation circuits under control of the light emission control end to control the pixel compensation circuit to drive the light emitting device to emit light; The voltage of the first power terminal and the voltage of the reference signal terminal are both higher than the voltage of the second power terminal. The pixel structure of claim 1 , wherein the pixel compensation circuit comprises: a data writing module, a compensation control module, a driving control module, a scanning signal end, a data signal end, and a compensation control end; wherein The data writing module includes a first end, a second end, and a third end, a first end of the data writing module is connected to the scanning signal end, and a second end of the data writing module is The data signal terminals are connected, and the third end of the data writing module is respectively connected to the first end of the driving control module and the first end of the light emitting device; the data writing module is configured to be in the Providing a signal of the data signal end to the first end of the driving control module under the control of the scanning signal end; The compensation control module includes a first end, a second end, a third end, and a fourth end, and the first end of the compensation control module is connected to the compensation control end, and the second end of the compensation control module Connected to the first output end of the voltage input control circuit, the second end of the drive control module, and the first node, respectively, the third end of the compensation control module and the second output of the voltage input control circuit The third end of the drive control module is connected, the fourth end of the compensation control module is connected to the first output end of the potential conversion circuit and the second node; the compensation control module is configured to be in the Charging is realized under the control of the first output end of the potential conversion circuit and the first output end of the voltage input control circuit, and the first node and the first end of the drive control module are controlled under the control of the compensation control end Passing, the threshold voltage of the drive control module and the voltage of the first end of the drive control module are stored in the first node; The drive control module is configured to drive the light emitting device to emit light under control of the first node and the second output of the voltage input control circuit. The pixel structure according to claim 1 or 2, wherein the potential conversion circuit comprises: a first conversion module and a second conversion module; wherein The first conversion module and the first power terminal, the reference signal terminal, the first potential conversion terminal, the first output end of the potential conversion circuit, and the second output of the potential conversion circuit Connected to the end; the first conversion module is configured to provide the voltage of the reference signal terminal to each of the pixel compensation circuits under the control of the first potential conversion end, and simultaneously provide the voltage of the first power supply terminal to Each of the light emitting devices; The second conversion module is respectively connected to the second power terminal, the second potential conversion terminal, the first output end of the potential conversion circuit, and the second output end of the potential conversion circuit; The two conversion module is configured to supply the voltage of the second power supply terminal to each of the light emitting devices and each of the pixel compensation circuits under the control of the second potential conversion terminal. The pixel structure according to claim 3, wherein said first potential conversion terminal and said second potential conversion terminal are the same signal terminal. The pixel structure according to claim 3 or 4, wherein the first conversion module comprises: a first switching transistor and a second switching transistor; wherein a gate of the first switching transistor is connected to the first potential converting end, a source is connected to the first power terminal, and a drain is connected to a second output end of the potential converting circuit; The gate of the second switching transistor is connected to the first potential converting end, the source is connected to the reference signal end, and the drain is connected to the first output end of the potential converting circuit. The pixel structure according to any one of claims 3 to 5, wherein the second conversion module comprises: a third switching transistor and a fourth switching transistor; wherein a gate of the third switching transistor is connected to the second potential converting end, a source is connected to the second power terminal, and a drain is connected to a second output end of the potential converting circuit; The gate of the fourth switching transistor is connected to the second potential converting end, the source is connected to the second power terminal, and the drain is connected to the first output end of the potential converting circuit. The pixel structure according to any one of claims 1 to 6, wherein the voltage input control circuit comprises: a fifth switching transistor and a sixth switching transistor; wherein a gate of the fifth switching transistor is connected to the charging control terminal, a source is connected to the first power terminal, and a drain is connected to a first output end of the voltage input control circuit; The gate of the sixth switching transistor is connected to the light emitting control end, the source is connected to the first power terminal, and the drain is connected to the second output end of the voltage input control circuit. The pixel structure of claim 2, wherein the data writing module comprises: a seventh switching transistor; wherein The gate of the seventh switching transistor is connected to the scanning signal end, the source is connected to the data signal end, and the drain is connected to the first end of the light emitting device. The pixel structure according to claim 2 or 8, wherein the compensation control module comprises: an eighth switching transistor and a capacitor; wherein a gate of the eighth switching transistor is connected to the compensation control terminal, a source is connected to a second output end of the voltage input control circuit, and a drain is connected to the first node; The capacitor is connected between the first node and the second node. The pixel structure according to claim 2 or 8 or 9, wherein the driving control module comprises: a driving transistor; wherein a gate of the driving transistor is connected to the first node, a source and the voltage input control A second output of the circuit is coupled and a drain is coupled to the first end of the light emitting device. A pixel structure according to any of claims 1-10, wherein N is greater than or equal to two. A driving method of a pixel structure according to any one of claims 2, 8-10, comprising: a charging phase, a discharging phase, a holding phase, and a lighting phase; wherein In the charging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each of the light emitting devices under the control of the first potential converting end, and simultaneously supplies the voltage of the reference signal terminal Providing a second node in each of the pixel compensation circuits; the voltage input control circuit provides a voltage of the first power supply terminal to a first node in each of the pixel compensation circuits under the control of the charge control terminal; The compensation control module implements charging under the common control of the first node and the second node; In the discharging phase, the potential conversion circuit supplies the voltage of the first power terminal to the second end of each of the light emitting devices under the control of the first potential converting end, and simultaneously supplies the voltage of the reference signal terminal Providing a second node in each of the pixel compensation circuits; the data writing module provides a signal of the data signal end to a first end of the driving control module under control of the scanning signal end; the compensation control The module turns on the first node and the first end of the driving control module under the control of the compensation control end, and the threshold voltage of the driving control module and the voltage of the first end of the driving control module All stored in the first node; In the holding phase, the potential conversion circuit supplies the voltage of the second power supply terminal to the second end of the light emitting device and the first of the pixel compensation circuits respectively under the control of the second potential conversion end Two nodes; In the light emitting phase, the potential conversion circuit supplies the voltage of the second power supply terminal to the second end of each of the light emitting devices and each of the pixel compensation circuits under the control of the second potential conversion end a second node; the voltage input control circuit supplies the voltage of the first power terminal to the third end of the drive control module in each of the pixel compensation circuits under the control of the illumination control terminal; the drive control module is The light emitting device emits light under the control of the first node and the third end of the drive control module. An organic electroluminescent display panel comprising: M column regions arranged in a matrix, and A pixel structure according to any one of claims 1 to 11, wherein the number of light-emitting devices in each of the pixel structures is equal; M is equal to N; The light emitting device and the pixel compensation circuit in each of the pixel structures are disposed in a region of the corresponding row, and one light emitting device and one pixel compensation circuit connected to the light emitting device are disposed in one region. A display device comprising the organic electroluminescence display panel of claim 13.

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